The present invention relates to a dual-purpose gas stove switch and, more particularly, to a dual-purpose gas stove switch for selective use with liquefied petroleum gas or natural gas.
Due to the difference of the fuels, there are two types of gas stoves for use with liquefied petroleum gas (LPG) or natural gas. Due to gas pressure difference between liquefied petroleum gas and natural gas, the switches and nozzles for LPG gas stoves are different from those for natural gas stoves. Specifically, the gas pressure of natural gas is lower than that of LPG such that the diameters of the gas passageways in the switches and nozzles of natural gas stoves are larger than the diameters of the gas passageways in the switches and nozzles of LPG gas stoves, resulting in problems to the users in purchase of the gas stoves and to the manufacturers and distributors in inventory and maintenance.
To solve these problems, dual-purpose gas stove switches have been proposed. Taiwan Patent Application No. 084210422 and Taiwan Patent of Addition No. 08421042-A01 disclose a gas stove switch including an inlet tube seat and a plurality of nozzles. An adjusting valve device mounted between each nozzle and the inlet tube seat. Each adjusting valve device includes a valve seat and a stem, wherein the valve seat is in communication with the inlet tube seat and one of the nozzles, and the stem is mounted in a center of the valve seat and includes a larger outlet and a smaller outlet both of which are in communication with an inlet. The stem can be turned to align the larger outlet with the nozzle for use with natural gas. On the other hand, the stem can be turned to align the smaller outlet with the nozzle for use with liquefied petroleum gas.
Taiwan Patent of Addition No. 084210422-A02, Taiwan Patent Application No. 087203024 and Taiwan Patent Application No. 095223271 disclose an auxiliary passageway between each nozzle and the inlet tube seat. An adjusting rod is mounted in the auxiliary passageway and can be turned to close the auxiliary passageway for use with liquefied petroleum gas. On the other hand, the adjusting rod can be turned to open the auxiliary passageway for use with natural gas.
Taiwan Patent Application No. 094219428 discloses a valve body including an inlet, an outlet, and an assembling hole between the inlet and the outlet. A throttle is pivotably mounted in the assembling hole and includes a passageway. A valve cap is mounted to an outer end of the assembling hole and includes an annular track having a groove. A rod is pivotably extended through the valve cap and connected to the throttle by two engaging portions. A cam is mounted to the rod and biased by a spring such that a lobe of the cam is restrained in the groove. The passageway of the throttle is in a closed position when the cam is in a disengaged position corresponding to the two engaging portions. The valve cap includes an axial rack in the track. When the cam is driven by the rod such that the lobe disengages from the groove and engages with the rack, the lobe can resiliently bear against the rack at any position to allow synchronous reciprocating axial adjusting movement of a switch for natural gas as well as gas flow control thereof. Furthermore, the valve cap includes an adjusting hole corresponding to the position of the rack. A stop can be locked in the adjusting hole to restrain rotation of the lobe on the rack for use with a switch for liquefied petroleum gas as well as flow control thereof. However, the stop can not be utilized to operate with the switch for natural gas and, thus, can not control the gas flow.
The above-mentioned gas stove switches fail to provide modification to the nozzles. Improvement of the gas stove switches in this regard is still possible.